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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Izolace alkaloidů druhu Geissospermum vellosii Allemão a studium jejich biologické aktivity III. / Isolation of alkaloids of the species Geissospermum vellosii Allemão and study of their biological activity III.

Růžička, Lukáš January 2020 (has links)
Růžička, L. Isolation of alkaloids from Geissospermum vellosii Allemão and study of their biological activity. Diploma thesis, Department of pharmacognosy, Faculty of Pharmacy in Hradec Králové, Charles University, Czech Republic, 2020. The aim of this diploma thesis are alkaloids from Geissospermum vellosii. This tree native in South America is commonly used for treatment of various diseases, including cognitive deficits in elder people1 . The study is based on previous research that was focused on inhibition of human cholinesterases and glycogensynthase 3 β(GSK-3 β), which can be used in treatment of Alzheimer disease. Incidence of this disease is rising up in the last decades and it represents a big burden for both health service and economy of developed countries2 . Isolation was carried out from crude crushed stembark. After extraction and agitation, 50.4 g of thick yellowish ether extract was obtained. This extract showed activity against cholinesterases (IC50 AChE = 15.19 ± 0.96 μg/ml and IC50 BuChE = 0.37 ± 0.049 μg/ml). Later, this extract was separated to 16 fractions by column chromatography. Fraction GV9 was chosen for additional research. Thin layer chromatography was carried out for purification and extraction of white crystalline alkaloid. Structure was determined by...
2

Izolace alkaloidů druhu Geissospermum vellosii Allemão a studium jejich biologické aktivity IV. / Isolation of alkaloids of the species Geissospermum vellosii Allemão and study of their biological activity IV.

Emrichová, Eliška January 2020 (has links)
Eliška Emrichová: Isolation of alkaloids of the species Geissospermum vellosii Allemão and study of their biological activity IV. Diploma thesis 2020. Charles University, faculty of Pharmacy in Hradec Králové, Department of Pharmacognosy. Key words: Geissospermum vellosii, bark, alkaloidal extracts, isolation of alkaloids, GC/MS analysis, biological aktivity, acetylcholinesterase, butyrylcholinesterase. The aim of this study was to isolate at least one pure alkaloid from the extract of Geissospermum vellosii Alemão bark. The whole process involved bark processing, to obtain summary and alkaloid extract and subsequent column chromatography. GV-4, one of the 16 obtained fractions, was separated into 5 subfractions. The GV-4bsubfraction was used to isolate pure alkaloids, processed by preparative thin layer chromatography and crystallization of pure compound. The structure of pure compound was determined by using NMR, GC-MS analysis and optical rotation. This compound was identified as anhydropereirine and was tested its inhibitory activity against human cholinesterases, AChE and BuChE. The alkaloids GV-1-a, GV-8-3-B, GV-9-c were isolated in the course of further work on the extract. Their inhibitory activity against GSK-3β was tested as well as their possibility to cross the blood-brain-barieer with...
3

Estudos farmacognósticos, fitoquímicos e atividade antileishmania de espécies Geissospermum (Apocynaceae)

SILVA, João Victor da Silva e 07 November 2016 (has links)
Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-06-26T15:16:33Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstudosFarmacognosticosFitoquimicos.pdf: 1850964 bytes, checksum: 4e29ee0419bc0d5c829bf082dac0181c (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-06-28T16:34:08Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstudosFarmacognosticosFitoquimicos.pdf: 1850964 bytes, checksum: 4e29ee0419bc0d5c829bf082dac0181c (MD5) / Made available in DSpace on 2017-06-28T16:34:08Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EstudosFarmacognosticosFitoquimicos.pdf: 1850964 bytes, checksum: 4e29ee0419bc0d5c829bf082dac0181c (MD5) Previous issue date: 2016-11-07 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / O objetivo deste trabalho foi realizar estudos farmacognósticos, fitoquímicos, atividade antileishmania e citotoxicidade de Geissospermum vellosii Allemão e Geissospermum sericeum Miers. Os estudos farmacognósticos foram realizados de acordo com a Farmacopeia Brasileira, V ed. (2010). Os extratos (EEGV e EEGS) foram obtidos através da maceração exaustiva com etanol (96° GL), seguido de concentração em rotaevaporador. O extrato etanólico foi fracionado por dois métodos: extração sob refluxo (frações de diferentes polaridades) e partição ácidobase (fração de neutro e fração acaloídica). As frações alcaloídicas (FAGV e FAGS) foram fracionadas em coluna cromatográfica contendo gel de Sephadex LH-20, e as subfrações resultantes foram analisadas em CCD e reveladas com reagente de Dragendorff e ultravioleta (365 nm). As subfrações F6FAGV e F6FAGS, onde se detectou alcaloides e bom rendimento, foram submetidas a novos fracionamentos em CLAE-DAD semipreparativa e a métodos espectrofotométricos. Na avaliação antileishmania utilizou-se formas promastigotas da espécie de Leishmania amazonensis (5 x 106 parasitas/100μL) tratada com diferentes concentrações das amostras por 24, 48 e 72h. A analise foi feita adicionando-se brometo de [3-(4,5- dimetiltiazol-2-il)-2,5-difeniltetrazólio] (MTT) em leitor de ELISA, em 490nm. A citotoxicidade foi avaliada através do ensaio de viabilidade celular com o MTT em células THP-1 diferenciadas e HepG2. Como critério de seleção foi utilizado o cálculo do índice de seletividade (IS), descrito como a razão entre a concentração citotóxica 50% em linhagens celulares e a Concentração inibitória 50% encontrado para protozoários, considerando-se pormissores valores ≥ 10. Os pós das plantas foram classificados como grosso (G. vellosii) e muito grosso (G. sericeum), de baixa densidade, com pH de 4,94 (G. vellosii) e 6,47 (G. sericeum), negativos para saponinas, com teor de cinzas e umidade dentro dos parâmetros estabelecidos pela Farmacopeia Brasileira, V ed. O estudo fitoquímico levou ao isolamento de um alcaloide indólico (F3F6FAGV) e um β-carbolínico (flavopereirina) de ambas as espécies. O fracionamento de EEGV e EEGS resultou em subfrações mais citotóxicas, porém o tempo de exposição e o refracionamento reduziram esta toxicidade. Na avaliação antripromastigota todas as amostras foram ativas e o fracionamento aumentou a atividade. A flavopereirina apresentou atividade tempo dependente e superior a anfotericina B. Entretanto, a associação da flavopereirina com alcaloide indólico e/ou a anfotericina B reduziu a seletividade desse metabólito. O fracionamento dos extratos contribui para elevação do índice de seletividade, sendo a seletividade da flavopereirina elevada (IS= 4893,3). Logo, o isolamento da flavopereirina contribui para redução da citotoxicidade e aumento da seletividade, caracterizando-se como um agente antileishmania promissor. / This study aimed to perform pharmacognostic and phytochemical studies, and assess antileishmanial activity and cytotoxicity of Geissospermum vellosii Allemão and Geissospermum sericeum Miers. The pharmacognostic study was carried out as described in the Brazilian Pharmacopoeia, 2010. The ethanol extracts (GVEE and GSEE) were obtained by exhaustive maceration with ethanol (96 ° GL), followed by concentration in rotaevaporator. The ethanol extract was fractionated using two methods: extraction under reflux (fractions of different polarities) and acid-base partition (neutral and alkaloid fractions). The alkaloid fractions (GVAF and GSAF) were fractionated on a chromatographic column with Sephadex LH-20 gel, and the resulting subfractions were analyzed on TLC, and reveled through Dragendorff reagent and ultraviolet (365 nm). The F6GVAF and F6GSAF subfractions, with alkaloids detected and good yield, were subjected to semi-preparative HPLC-DAD, and spectrophotometric methods. For evaluating the antileishmanial activity, promastigote forms of Leishmania amazonensis at a concentration of 5 x 106 parasites/100μL were treated with the samples at different concentrations for 24, 48 and 72h. The analysis was done adding [3- (4,5-dimethylthiazol-2-yl) -2,5- diphenyltetrazolium bromide (MTT) to the samples in an ELISA reader at 490 nm. Cytotoxicity was assessed through cell viability assay with MTT in differentiated THP- 1 cells and HepG2. As a selection criteria, the selectivity index (IS) was calculated as the ratio between the cytotoxic concentration 50% in cell lines, and the inhibitory concentration 50% found for protozoa, considering as promising values ≥ 10. The plant powder was classified as thick (G. vellosii), and very thick (G. sericeum), low density, with pH 4.94 (G. vellosii) and 6.47 (G. sericeum), negative to saponins, with ash and moisture within the parameters established by the Brazilian Pharmacopoeia V. In the phytochemical study, we suggest the isolation of an indole alkaloid (F3F6FAGV) and a β-carbolinic (flavopereirine) from both species. The fractionation of GVEE and GSEE resulted in more cytotoxic subfractions, but the exposure time and refractionation reduced this effect. In the antipromatigota assay, all samples were active, and the fractionation increased the activity. The flavopereirine presented time-dependent activity greater than amphotericin B. However, the flavopereirine in association with indole alkaloid and/or amphotericin B reduced the selectivity of this metabolite. The extracts fractionation increases the selectivity index, and the selectivity of flavopereirin is high (SI = 4893.3). Therefore, the isolation of flavopereirine contributes to reduce cytotoxicity and increase selectivity, showing itself as a promising antileishmanial agent.
4

Atividade antibacteriana de plantas medicinais frente á bactérias multirresistentes e a sua interação com drogas antimicrobianas / Antibacterial activity of medicinal plants used against multi-resistant bacteria and their interaction with antimicrobial agents

SARAIVA, Rosa Márcia Corrêa 28 August 2012 (has links)
Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-07-21T16:30:47Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AtividadeAntibacterianaPlantas.pdf: 1225761 bytes, checksum: 3b7a35e5a304fbe1d5d13f4ded77d104 (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-09-05T17:44:03Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AtividadeAntibacterianaPlantas.pdf: 1225761 bytes, checksum: 3b7a35e5a304fbe1d5d13f4ded77d104 (MD5) / Made available in DSpace on 2014-09-05T17:44:03Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AtividadeAntibacterianaPlantas.pdf: 1225761 bytes, checksum: 3b7a35e5a304fbe1d5d13f4ded77d104 (MD5) Previous issue date: 2012 / O controle de micro-organismos infecciosos multirresistentes às vezes é ineficaz mesmo com o desenvolvimento de novos antibióticos. Diversos extratos de plantas medicinais têm efeitos antimicrobianos o que pode representar uma alternativa terapêutica para doenças infecciosas, principalmente quando associados aos antibióticos de uso clínico. O objetivo do trabalho foi avaliar a atividade antibacteriana de plantas medicinais sobre bactérias multirresistentes e os efeitos de sua interação com drogas antimicrobianas. Foi determinada a atividade antibacteriana de extratos e frações das plantas Eleutherine plicata (marupazinho), Geissospermum vellosii (pau-pereira) e Portulaca pilosa (amor-crescido) frente a isolados de Staphylococcus aureus Oxacilina Resistente (ORSA) e de Pseudomonas aeruginosa multirresistente, provenientes de processos clínicos humanos, assim como a interação destes produtos vegetais com drogas antimicrobianas de uso clínico. A atividade antibacteriana foi determinada pelo método de disco difusão em ágar Muller Hinton e a Concentração Inibitória Mínima (CIM) pela técnica de microdiluição em placas utilizando caldo Muller Hinton como meio de cultura e resazurina a 0,01% como revelador de crescimento bacteriano. Os extratos e frações foram testados nas concentrações de 500, 250, 125, 62,5, 31,2 e 16,2 μg/mL dissolvidos em DMSO a 10%. As plantas E. plicata e G. vellosii demonstraram atividade contra os isolados ORSA com CIM de 125 μg/mL, enquanto que P. pilosa teve ação sobre os isolados de P. aeruginosa multirresistentes com CIM de 250 μg/mL. Ocorreram 25% de sinergismo e apenas 5% de antagonismo entre as 120 interações de produtos vegetais e drogas antimicrobianas testadas. Frente aos isolados ORSA houve sinergismo com as drogas ciprofloxacina, clindamicina e vancomicina tanto com os derivados de E. plicata como os de G. vellosii. Os produtos de P. pilosa potencializaram a ação das drogas aztreonam, cefepime e piperacilina+tazobactam frente aos isolados de P. aeruginosa multirresistentes. Os resultados comprovaram o potencial das plantas E. plicata, G. vellosii e P. pilosa no controle de infecções bacterianas envolvendo fenótipos multidrogas resistentes (MDR) e que a sua interação com drogas antibacterianas pode representar uma nova alternativa na terapia destas infecções. / Infection control of the multidrug-resistant microorganisms sometimes is ineffective even with the development of new antibiotics. Many herbal extracts have antimicrobial effects and may represent an alternative therapy for infectious diseases, mainly when associated with antibiotics of clinical use. The aim of this study was to evaluate the antibacterial activity of medicinal plants in multidrug-resistant microorganisms and their interaction with antimicrobial agents. We evaluate the antibacterial activity of plant extracts and fractions of Eleutherine plicata (“marupazinho”) Geissospermum vellosii (“pau-pereira”) and Portulaca pilosa (“amor-crescido”) against isolates of Oxacillin-Resistant Staphylococcus aureus (ORSA) and multi-resistant bacteria Pseudomonas aeruginosa, from human clinical isolates. Also we evaluate interaction of these plant extracts with antimicrobial agents of clinical use. The antibacterial activity was determined by disk diffusion on Mueller Hinton agar and the Minimum Inhibitory Concentration (MIC) by micro dilution plate technique using Muller Hinton broth as culture medium and 0.01% resazurin as a developer of bacterial growth. The extracts and fractions were tested at concentrations of 500, 250, 125, 62.5, 31.2 and 16.2 μg/mL dissolved in 10% DMSO. Plants E. plicata and G. vellosii demonstrated activity against ORSA isolates with MICs of 125 μg/mL, whereas P. pilosa had an effect on the isolates of P. aeruginosa with MIC of 250 μg/mL. There were 25% of synergism and only 5% of antagonism of all 120 plant and antimicrobial agents interaction tested. ORSA isolates had synergistic interaction with ciprofloxacin, clindamycin and vancomycin agents and with both plant derivatives of E. plicata and G. vellosii. The derivatives of P. pilosa potentiated the action of the aztreonam, cefepime and piperacillin + tazobactam agents compared to the isolates of P. aeruginosa multidrug-resistant. The results shows therapeutic potential of E. plicata, G. vellosii and P. pilosa in the control of bacterial infections involving multidrug-resistant phenotype (MDR) and its interaction with antibacterial agents may represent a new alternative in the therapy of these infections.

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